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| Titel |
Evaluation of factors controlling large earthquake-induced landslides by the Wenchuan earthquake |
| VerfasserIn |
X. L. Chen, H. L. Ran, W. T. Yang |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1561-8633
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| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Science ; 12, no. 12 ; Nr. 12, no. 12 (2012-12-12), S.3645-3657 |
| Datensatznummer |
250011256
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| Publikation (Nr.) |
 copernicus.org/nhess-12-3645-2012.pdf |
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| Zusammenfassung |
| During the 12 May 2008, Wenchuan earthquake in China, more than 15 000 landslides
were triggered by the earthquake. Among these landslides, there
were 112 large landslides generated with a plane area greater than
50 000 m2. These large landslides were markedly distributed closely
along the surface rupture zone in a narrow belt and were mainly located on
the hanging wall side. More than 85% of the large landslides are
presented within the range of 10 km from the rupture. Statistical analysis
shows that more than 50% of large landslides occurred in the hard rock
and second-hard rock, like migmatized metamorphic rock and carbonate rock,
which crop out in the south part of the damaged area with higher elevation
and steeper landform in comparison with the northeast part of the damaged
area. All large landslides occurred in the region with seismic intensity
≥ X except a few of landslides in the Qingchuan region with seismic
intensity IX. Spatially, the large landslides can be centred into four
segments, namely the Yingxiu, the Gaochuan, the Beichuan and the Qingchuan
segments, from southwest to northeast along the surface rupture. This is in
good accordance with coseismic displacements. With the change of fault type
from reverse-dominated slip to dextral slip from southwest to northeast, the
largest distance between the triggered large landslides and the rupture
decreases from 15 km to 5 km. The critical acceleration ac for four
typical large landslides in these four different segments were estimated by
the Newmark model in this paper. Our results demonstrate that, given the
same strength values and slope angles, the characteristics of slope mass are
important for slope stability and deeper landslides are less stable than
shallower landslides. Comprehensive analysis reveals that the large
catastrophic landslides could be specifically tied to a particular
geological setting where fault type and geometry change abruptly. This
feature may dominate the occurrence of large landslides. The results will be
useful for improving reliable assessments of earthquake-induced landslide
susceptibility, especially for large landslides which may result in serious
damages. |
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